1. Field of the Invention
This invention relates to power tool attachments capable of attaching to a rotary power source such as a hand drill. More particularly, this invention relates to a circular saw and a drum sander attachment driven by a gear mechanism housed within a tubular support member.
2. Description of the Prior Art
In today's society, there is a continuous demand for carpenters, contractors, etc. With the demand for skilled woodworkers comes a demand for instruments which allow precision cutting and sanding. It is difficult to both quickly and accurately do precision cutting and sanding.
To sand in tight spaces has generally required hand sanding which takes tremendous time and effort. Precision cutting would usually require the use of a hand held jigsaw to do cutting such as that required for cutting out electrical outlet boxes or medicine cabinet openings which recess into walls.
U.S. Pat. No. 3,506,044 discloses a portable power tool driven by a gear assembly. While this invention does include a gear assembly, it lacks the adaptability of the present invention. The present invention can be fixed to any hand drill or other such power source and does not require its own internal motor. Because of the lack of a motor, the present invention is more affordable to the consumer seeing that only attachments need to be bought.
U.S. Pat. No. 4,574,481 teaches using gears for driving a shaft but does not teach the attachments according to the present invention. The patent to Ericsson is for a portable motor, not for attachments. Undoubtedly a motor such as disclosed by Ericsson could be adapted for use with the present invention, but using the motor of Ericsson takes away the maneuverability of the present invention. A hand held power source such as an electric drill is much more advantageous.
U.S. Pat. No. 3,505,733 to Holden discloses a power operated hand tool which looks remotely like the cutting attachment of the present invention but is driven by transverse oscillation of a drive means.
Moreover, none of these patents teach an easy way of controlling whether the device is on or off, which is an essential feature for precise, close-in work. These patents do not use the simple structure of this invention.
A type of circular saw that is run by a drill is known in the art. This device looks like a small version of a power circular saw. However, instead of having a motor built into the saw, this device has a space where an external driving means can be attached to the saw. This saw is cumbersome to use as it requires one hand to guide the saw and one hand to operate the power supply. The circular saw is unable to do as fine a job as the present invention as the circular saw is not capable of getting up close to walls or doing precision woodworking. The present invention is better as it is easier to guide and can perform more precise cutting.